Organo-boron compositions and method for production thereof



United States Patent O ORGANO-BORON COMPOSITIONS AND METHOD FORPRODUCTION THEREOF Application October 9, 1952, Serial No. 313,851 20Claims. c1. 252-49.6

This invention relates to organo-boron compositions and to a method forthe production thereof. More particularly, the invention relates tostable, oil-soluble, organo-boron compositions which may be utilized asadditives for lubricants and fuels; to lubricants and fuels containingsuch organo-boron compositions; and to methods forthe productionthereof.

In general, organo-boron compounds known in the prior art demonstratesuch instability as to preclude commercial acceptance as lubricantadditives. Conventional borate esters, in particular, are known to berapidly bydrolyzed to precipitate substantial quantities of boric acid,and hence are considered infeasible for use in substantial quantities.as additives for lubricants.

It is a primary object of this invention to provide a method forproducing from conventional paraffinic petroleum fractions, novelorgano-boron compositions.

It is a further primary object of the invention to provide novelorgano-boron compositions which demonstrate unusual stability whenblended with hydrocarbon oil compositions. 1

It is an additional object of the invention to provide organo-boroncompositions of a new typev which are stable when blendcd with syntheticlubricating compositions, including the polyalkylene glycols such as thepolypropylene glycols, polybasic acid esters such as di-Z-ethylhexylsebacate, and the like.

It is an additional object of the invention to provide novelorgano-boron compositions which, when added to lubricating compositionsof both the mineral oil and the synthetic type, will improve theoxidation or wear characteristics thereof.

' It is a further object of the invention to provide lubricantcompositions containing the novel organo-boron -compositions of theinvention.

It is still another object of the invention to provide novelorgano-boron compositions which are useful as additives to improve theperformance characteristics of gasoline, diesel fuels, and the like.

It is also an object of the invention to provide novel internalcombustion engine fuels containing the organoboron compositions of theinvention.

It is an additional object of the invention to provide a method forenhancing the resistance of or'gano-boron compositions to decompositionby hydrolysis.

In accordance with this invention, it has been discovered that novelorgano-boron compositions can be produced by passing a free-oxygencontaining gas through a normally liquid parafi'inic petroleum fractionhaving a boiling point in the range of about 350 F. to about 800 F.,maintained at a temperature within the range of about 305 F. to about385 F.; there being available for reaction in said fraction fiom about 1to about 3 chemical equivalents of an acid selected from the groupconsisting of orthoboric acid. and meta-boric acid, per mole ofparaffinic hydrocarbon; said gas being passed-through said fraction atarate requisite to. provide not more than about 0.6 cubic feet of oxygenper hour per gallon of said fraction;

2,721,180 Patented Oct. 18, 1955 ICC to produce a crude reaction productcontaining at least about 0.2% by weight of chemically combined boron.

The above-defined process conditions are critical to the production oforgano-boron compositions characterized by the properties required toachieve various of the aforementioned objects of this invention.

It is of paramount importance that an additive form no appreciablequantity of solids, i. e. by sedimentation or hydrolysis, when blendedwith a lubricant or fuel. The formation of such solids in substantialquantity has resulted in the nonacceptance by the industry of manypreviously known organic boron compositions as additives for lubricantsand fuels.

To the end that organo-boron compositions which do not form an excessivequantity of solid materials by sedimentation or hydrolysis may beproduced, it is critical to the process of this invention that not morethan about 3 chemical equivalents of an acid selected from the groupconsisting of ortho-boric acid and meta-boric acid be available per moleof paralfinic hydrocarbon present in the course of the oxidationreaction.

It is further critical to the invention that the relative concentrationof orthoor meta-boric acid in the reaction mixture not fall below about1 equivalent per mole of parafiinic hydrocarbon present in the startingmaterial. The availability to the reaction of a relative quantity oforthoor meta-boric acid substantially less than 1 equivalent per mole ofparafiinic hydrocarbon present, results in the formation of a crudereaction mixture containing a quantity of chemically combined boroninsutncient for the feasible production therefrom of an organo-boroncomposition having utility as a lubricant or .fuel additive. It iscritical to the process of this invention that the reaction mixtureobtained therefrom contain at least about 0.2% by Weight of chemicallycombined boron.

The interaction of hydrocarbon, oxygen, and boric acid in the process ofthis invention results in the formation of water. The quantity of waterformed is a function of the rate of supply of oxygen to the reactionmixture. Under the conditions defined for the process of this invention,dynamic equilibria are established between the ortho-boric acid,meta-boric acid, forms of boric anhydride less hydrated than orthoandmeta-boric acid, and boric anhydride per se. Such equilibria may begenerally indicated by the following equation:

As ortho-boric acid and meta-boric acid are consumed by the reaction,the above equilibria are displaced to the right, and additionalquantities of ortho-boric acid or meta-boric acid are made available tothe reaction. As the reaction proceeds, all of the boric acid formingmaterials present in the reaction mixture may ultimately be converted tothe orthoor meta-borate form essential to the process.

It is apparent that the quantity of ortho-boric acid or meta-boric acidavailable for reaction at any time during 7 the process is a function ofthe quantity of Water present in the reaction mixture, and hencedependent upon the rate of supply of oxygen to the reaction mixture.

To maintain an adequate concentration in the reaction mixture, oforthoor meta-boric acid available for reaction, it is critical thatoxygen be supplied to the reaction mixture at a rate not substantiallygreater than about 0.6 cubic feet of oxygen per hour per gallon of theparafiinic petroleum fraction employed as a starting material.

If oxygen is supplied at a rate substantially greater than the specifiedcritical maximum of 0.6 cubic feet per hour per gallon of paraffinicpetroleum fraction employed as a starting material, water is removedfrom the reaction mixture and the aforementioned equilibria displacedfar to the left.

i the type described with reference to Fig. l.

3 Under such conditions a product is formed which is characterized byexcessive sedimentation and hydrolysis when blended with lubricatingcompositions such as hydrocarbon oils and synthetic lubricants and withfuels. Such compositions are not contemplated by this invention.

Preferably oxygen is supplied to the reaction mixture I at a rate offrom. about 0.3 to about 0.5 cubic feet per hour per gallon ofparaflinic petroleum fraction utilized as a starting material. Thecorresponding air rate is a critical'maximum of about 3.0 cubic feet perhour per gallon of petroleum fraction utilized as a starting material.Likewise the preferred range of rate of supply of air is from about 1.5to about 2.5 cubic feet per hour per gallon of petroleum fractionstarting material.

The criticality ofthe upper limit of the rate of supply of free-oxygenof about 0.6 cubic feet of oxygen per hour per gallon ofpetroleum'fraction starting material is evidenced by Figures 1 and 2. InFig. 1, there is graphically represented the relationship between therate of supply of free-oxygen in the form of air to the reactionmixfiltered reaction product to a temperature of about 300 F at'anaverage pressure of about 2 mm. of mercury.

The degree of hydrolysis was determined by exposing 100 millilitersamples of the aforementioned blends to the atmosphere for twenty-eightdays under proper precautions to exclude the introduction of foreignmaterials. At the termination of the twenty-eight day test period, theoil blend samples were filtered through sintered glass fibers of mediumporosity and the residua so obtained were washed with 150 cc. of naphthato remove occluded oil. The residua were then dried and weighed and thedegree of hydrolysis as weight percent of th original oil blends wascalculated.

It will be observed from an examination of Fig. 1 that the character'ofthe product obtained changes rapidly as the rate of supply of airexceeds substantially the critical upper limit of about 3.0 cubic feetper hour per gallon of petroleum fraction starting material. Theproducts formed at rates of air supply appreciably in excess of about3.0 cubic feet per hour per gallon of petroleum fraction startingmaterial demonstrate progressively increasing and substantially greaterhydrolysis than the products formed by the method of this invention.Such hydrolytically unstable products are therefore not suitable asadditives for lubricating oils, and are not contemplated by thisinvention.

In Fig. 2 there is graphically represented the relationship between thevolume percent of sedimentation formed in blends of No. 1100 aviationoil containing about 15% by volume of the crude-organo-boroncompositions of It will be observed by reference to Fig. 2 that thereare produced organo-boron compositions which demonstrate a progressivelyincreasing and excessive degree of sedimenta- 7 tion when the rate ofsupply of air to the reaction mixture substantially exceeds the criticalupper limit of about 3.0 cubic feet of oxygen per hour per gallon ofparafiinic petroleum fraction starting material. Such compositions arenot contemplated by this invention, and are not useful as lubricatingoil or fuel additives. The volume percent of sedimentation wasdetermined by incorporating into A. S. T. M. cone-shaped calibratedcentrifuge tubes (see specification A. S. T. M. B96-47T) N0. 1100aviation oil blends containing 15% by weight of crude organo-boroncompositions of the type described with reference to Fig. 1. The blendsin the tubes were heated, if necessary, at a temperature of about 130-140 F., to effect complete solution of the organo-boron material in theoil, and thereafter permitted to stand, stoppered, at room temperaturefor a period of three days. At the expiration of the three-day period,the blended oil was centrifuged for two hours at 1500 revolutions perminute and the amount of sedimentation of insoluble material recorded.The centrifuging was repeated at several threeday intervals, untilconstant readings were obtained. From such readings the volume percentofsedimentation was determined. 7 V v V The data reflected by Figs. 1and 2 were all obtained from oxidation reactions conducted at atemperature of about 355 F. with reaction mixturesin which there wereabout 2 equivalents of ortho: or meta-boric acid available per mole ofparaffinic hydrocarbon present. Analogous results are obtained as therelative concentration of orthoboric acid or meta-boric acid, and thetemperature,fare varied within the limits required by this invention.Such variations in reaction conditions effect some shift in the specificlocation of the curves on the graphs.

The charge stock utilized in developing Figs. 1 and 2 was a whitemineral oil having a C-16 to C-17 molecular weight range. This chargestock was characterized by a flash point of 275 F., a fire point of 300F., a viscosity at 100 F. of 39.6 S.-U. S., a viscosity at 210 F. of3110 S. U. S., a cloud point of 28 F., a distillation range of 523 F. to703 F., and a density of 20 C. of 0.8014.

Figs. land 2 demonstrate that, the compositions pro} duced in accordancewith the method of this invention are characterized by properties whichdistinguish them in kind from compositions obtained by supplying oxygento the reaction mixture at a rate substantially in excess of 0.6

. products of this invention may be represented by the cubic feet perhour per gallon of paraflinic petroleum frac tionstarting material. V .1

Elemental analyses demonstrate that the products of the process of thisinvention are substantially lower in molecular Weight and of differentmolecular structure thanproducts obtained by supplying oxygen to theoxidation reaction mixture at a rate substantially in excess of theupper limit critical to this invention. These facts are evidenced bydata recorded in Table I. i

The data appearing in Table I indicate that predominant formulai ROB-(OX) 2 whereas the products resulting from the utilization of asubstantially greater rate of supply of oxygen to the reaction mixturemay be represented by the molecular structure:

may be employed at the initiation of the reaction boric anhydride or anyof the various boric acids, including pyro-boric acid, meta-boric acid,and the like. Boric anhydride and the various boric acids differ onlywith respect to the degree of hydration. Consequently, as the reactionproceeds and water is formed, boric acids less hydrated than orthoandmeta-boric acid will be converted to the metaand orthoform.

A preferred embodiment of the invention entails the utilization as astarting material of a mixture containing from about 50% to about 90% byweight of boric anhydride and about 50% to about by weight of orthoormeta-boric acid. Such a combination of boric anhydride and boric acidfunctions synergistically to substantially increase the yield of thedesired organo-boron compositions, and therefore constitutes a salientfeature of this invention. The advantage stemming from the use of amixture of boric anhydride and orthoor meta-boric acid, within theaforementioned range of relative proportions, is graphically representedby Fig. 3 Which shows the relationship between the yield of organo-boronmaterial and the relative percentage of orthoor meta-boric acid andboric anhydride.

Significantly, it has been discovered that the boric acid residuaresulting from the process of this invention normally constitutes amixture of orthoor meta-boric acid and boric anhydride in proportionsfalling within the above specified range. Generally such residua containfrom about 70% to about 80% by weight of boric anhydride and about 20%to about 30% of boric acids. An important aspect of the inventiontherefore embraces the utilization as starting materials of such boricacid or boric anhydride residua for the formation of additionalorganoborcn compositions from fresh charges of parafiinic hydrocarbonstarting material.

It is further critical that the process of this invention be effected ata temperature within the range of about 305 F. to about 385 F. If thelower temperature limit of about 305 F. is not observed the resultingreaction is long-delayed, due to an apparent induction period in whichno organo-boron compounds are produced. The reaction mixture resultingfrom the practice of the invention at a temperature below the specifiedminimum of 305 F. furthermore contains substantially less than about0.2% by weight of chemically combined boron and hence is entirely beyondthe purview of this invention. It is critical to the process of thisinvention that there be obtained a crude reaction mixture containing atleast about 0.2% by weight of chemically combined boron, to the end thata product may be obtained which is of value as a lubricant and fueladditive.

The upper temperature limit of about 385 F. is essential to obtain apractical yield of organo-boron materials, of the type with which thisinvention is concerned. At temperatures appreciably in excess of 385 F.,significant quantities of such organo-boron composition are notobtained. The preferred temperature range is from about 340 F. to about365 F.

Under the conditions specified for the process of this invention, thereaction requisite to form the desired organo-boron materials isnormally completed in about five to about ten hours. It is essentialthat the reaction be not unduly extended for the reason thatexhaustively oxidized mixtures yield organo-boron compositions whichdemonstrate excessive sedimentation and hydrolysis and which thereforeare unsuitable as additives for lubricants and fuels. It has beendetermined that the rate of absorption of oxygen decreases markedly atapproximately the same point in the reaction that the quality of theorganoboron composition begins to be adversely efiected by excessiveoxidation. The proper end-point of the reaction is thereforedeterminable by observation of the rate of absorption of oxygen to notethe point at which such rate markedly decreases. When air is utilized asthe source of oxygen, it has been determined that the reaction isadvisedly. interrupted when the oxygen in the exit gases approximates 5%by volume.

It has further been determined that the rate of ahsor'p tion of borondecreases simultaneously with the rate of absorption of oxygen and is afurther criterion of the proper end-point of the reaction. Thereforefrequent observation of the boron content coupled with gas analysesrequisite to determine the rate of oxygen absorption, permitstermination of the reaction at the proper'endpoint.

Free-oxygen may be supplied to the reaction mixture either as theessentially pure elemental gas or in admixture with any desired inertgas. For obvious economic reasons, air preferably is employed. In somecases it has proved desirable to preheat the air or other source offree-oxygen prior to supplying the same to the reaction mixture in theprocess of this invention. Preheating of the air to a temperature offrom about 160 F. to about 210 F. has proved beneficial.

The process of this invention is preferably carried out in a cylindricalvessel. It has been determined that in such vessels it is highlydesirable that the reaction mixture conform to a liquid depth/ arearatio of at least about 2, to the end that a maximum yield of thedesired products may be obtained. In such cylindrical vessels it hasbeen discovered that if the liquid depth/area ratio falls sub stantiallybelow 2, the yield of the desired material decreases with greatrapidity. The term area as herein employed refers to the cross-sectionalarea normal to the cylindrical axis.

Conventional oxidation catalysts are preferably employed in the processof the invention. Such catalysts includ manganese naphthenate, manganesestearate, copper, cobalt, and nickel naphthenates, and the like. Ifdesired, the process of this invention can be practiced without acatalyst.

The starting materials useful in the production of the organo-boroncompositions of this invention must be selected not only on the basis ofthe yield of organoboron compositions produced, but also in view of thefact that there must be obtained an ultimate product which will notunduly increase the pour point of the lubricants or fuels to which theproduct may be added. In general, normally liquid mineral oil solubleparaflins having a boiling point in the range of about 350 F. to about800 F. may be employed. Those skilled in the art will well appreciatethat solid, wax type materials may be expected to yield solid productsless desirable as lubricant or fuel additives. Preferably the startingmaterials utilized in the process of the invention embrace paralfinicpetroleum fractions boiling from within the range of about 500 F. toabout 600 F. If separation of the organoboron materials is desired, itis further preferred that fractions having an over-all boiling pointrange of not more than about F. be utilized to facilitate the recoveryand purification of the organo-boron compounds suitable for blending inlubricants and fuels.

Essentially pure paraflins have been discovered to give the greatestyield of the desired products. To thisend, it is desirable to removesubstantially completely from the charge stocks such aromatics as may bepresent. Naphthenes and olefins are also desirably removed from thecharge stock prior to utilization in the process of this invention.Recovered, unoxidized charge stock from pre* vious runs, in accordancewith the method of the invention, may be utilized as a starting materialeither per se or subsequent to a light earth or acid treatment. An idealcharging stock is one characterized by molecular weight sufficientlyhigh that the crude reaction mixture will contain a suflicient yield ofborates and have such volatility characteristics that no distillationthereof will be necessary prior to utilization of the reaction mixtureas a lubricant. Such a crude product would be characterized by aviscosity in the light oil range and would not necessitate excessiveconcentration.

'tion mixtures produced by the process of the invention 'to remove thelower boiling components thereof. In

general, distillation at a pressure of from about 0.3 mm. of mercury toabout 100 mm. of mercury at a temperature of from about200 F. to about,425 F. is adequate for this purpose: Such crude organo-boroncompositions normally boil at a. temperature above the boiling range ofthe charge stock utilized, and hence unreacted charge stock may beremoved by the distillation process. In some instances, it is desirableor preferable to hydrolyze the crude organo-boron compositions of theinvention with water or aqueous alkali to produce alcohols. Generallyspeaking, such hydrolysis may be effected in conventional manner bysubjecting the crude organoboron compositions to the action of water oraqueous alkali at a temperature of from about 50 F. to about 300 F. fora period of from about 0.5 minute to about 120 minutes. The preferredaqueous alkalis are aqueous solutions of alkali and alkaline earth metalhydroxides, particularly sodium hydroxide in a concentration such thatthe pH falls within the range of from about 10 to about 14.

a It may be desirable in some instances to purify by distillation, thealcohols obtained by hydrolysis and thereafter reesterify the purifiedalcohols with boric acid to produce purified boron compositions usefulas fuel or lubricant additives. Conventional procedures for effectingesterification of alcohols with boric acid may be employed. It has beendetermined that such esterification may desirably be effected bytreating the alcohols with boric acid or boric anhydride at atemperature of from about 50 F. to about 300 F. Normally esterificationis complete in from about 0.5 minute to about 120 minutes. It has'beendiscovered .that the presence of weakly basic'inorganic'compounds insmall amounts in the reaction mixture of the process of this inventionwill resuit in the ultimate production of organo-boron compositions 'ofimproved sedimentation characteristics. Materials useful for thispurpose, in general, are those which form saturated aqueous solutionscharacterized by a pH of between about 7 and about 10. Examples ofcompounds which may be so employed include aluminum hydroxide, borax andother alkali and alkaline earth 'metal borates, such as NaHzBOz, NaOBO,Ca(OBO)2,

cameos, KHzBO3, and the like.

, In general, from about 0.1% to about 5.0% by weight of such materials,based on the quantity of paraffinic petroleum fraction utilized, cansatisfactorily be employed.

Significantly, the hydrolytic stability of the organoboron compositionsof this invention may be enhanced by the'incorporation therein oforganic carbinol compounds (i. e. compounds derived from methanol,CHaOH) and particularly high molecular weight aliphatic alcohols,polyalkylene glycols, and the like. In general, there may be employedorganic hydroxy compounds having from about 2 to 100 carbon atoms whichare soluble in the organo-boron compositions of this invention. In

7 Table II there is recorded comparativedata showing the effects of theincorporation of such organic hydroxy materials into aviation oilcontaining 30% by weight of the crude organo-boron compositions of thisinvention produced by the methods described with reference to Figs. 1and'2.

8 TABLE II Efiect of organic hydroxy compounds on hydrolytic s tabilityof organo-boron compositions in 30% by volume concentration in 1100grade aviation oil 1 Weight Volume Percent Percent of solids HydroxyCompound figigrmoxy E E by pound 2 None 0. 23 Heptad Pr-mml 1. O 0. 10Heptadonann'l V 5, 0 0, 12 Polyethylene Glycol, Mol. Wt. 200 1. 0 0. 09Polypropylene Glycol Compounds:

Viscosity 210 F., 177 S. U. S! 1. 0 0.05 Viscosity 210 F., 125 S. U.s. 1. 0 0.10 Viscosity 210 F., 781 S. U. S. 1.0 0.09 Tctrademnnl 1. 0 0.09 Glycerin .L 1. 0 0. 01

1 Of the type described with reference to Fig. 1.

= As determined by method described with reference to Fig. 1. 1 Ucon LB1145 lubricant.

4 Ucon 50 HB 660 lubricant.

5 Ucon 50 HB 5100 lubricant.

A salient feature of the invention therefore embraces the incorporationof such aliphatic organic hydroxy compounds into the organo-boroncompositions of the invention, either alone or in conjunction withlubricating oil, fuels and the like, to impart greater hydrolyticstability thereto. The preferred relative concentration of the organiccarbinol compounds to the organo-boron compositions of the invention isfrom about 1.0% to about 5.0% by volume thereof. Preferred organo-boroncompositions include the polyalkylene glycols including the polyethyleneglycols and the polypropylene glycols, especially the polyalkyleneglycols and derivatives useful in synthetic lubricants and havingviscosities at 210 F. within the range of from about ,38 S. U. S. toabout 800 S. U. S., glycerin, pentarythritol, mannitol, sorbitol, andlike hexitols; monohydric paraffin alcohols, particularly those havingfrom 5 to carbon atoms, including amyl alcohol, hexanol, and the variousisohexanols, heptanols, octanols, nonanols, decanols, dodecanols,tetra-v decanols, octadecanols, alcohols prepared by the methodsdescribed in this invention, and the like.

The organo-boron compositions of this. invention of both the crude andpurified type enjoy particular utilitylas additives to improve theoxidation characteristics of lubricating oils. Of particularsignificance is the fact that the organo-boron compositions of theinvention, per se, demonstrate lubricating properties and in consequencethereof can be used in large relative proportions, up to about 100%, inlubricant blends. Preferably the organo-boron compositions of thisinvention are blended in a concentration of about 5% to about by weightwith conventional lubricants such as hydrocarbon oils or syntheticlubricants such as poly propylene glycols and polyesters.

It is within the purview of this invention to provide con-. centratescontaining a lubricant and from about 30% to about by weight of theorgano-boron compositions of the invention which concentrates may bediluted to produce the ultimate commercial products.

Significantly, the crude organo-boron compositions of this inventiondemonstrate greater oxidation inhibition characteristics than do thepurified organo-boron compositions of the invention, as evidenced byTable III appearing hereinafter.

'It has been determined that the organo-boron compositions of thisinvention are surprisingly more effective as. anti-oxidants whenincorporated in lubricants containing a substantial proportion ofaromatics, than they are when incorporated in lubricants which are morehighly refined and which therefore are substantially free of aromatics.This result is indeed unexpected and remarkable. Refining trends andtechniques in the industry in recent years have been directed towardremoval of aromatics. Deposit-forming tendencies of mineral oils aredirectly related to the degree of refine-nent, for example, unextractedbright stock forms approximately two and onehalf times as mush depositas does 1100 grade aviation oil of the type previously described, incomparative steel strip tests. This relationship is reversed in thepresence of the organo-boron compositions of the invention. The lesshighly refined mineral oil stocks containing the compositions of theinvention form substantially less deposit in comparative steel striptests than do more highly refined oils substantially free of aromaticscontaining a like relative quantity of the organo-boron compositions ofthe invention. Furthermore, the less highly refined oil containing theorgano-boron products of the invention demonstrate markedly lessincrease in viscosity than do the more highly refined oils containinglike amounts of the organo-boron compositions of the invention when theoil blends are subjected to conditions conducive of oxidation.

There is recorded in Table III data representative of the anti-oxidanteffect, as evidenced by steel strip tests of both the crude and thepurified organo-boron compositions of this invention when incorporatedin the indicated oil stocks in a concentration of to 15% by weight. Thesteel strip tests were carried out by maintaining 21 steel strip at atemperature of 600 F. in contact with a constant flow of the test oilfor a period of six hours, at the end of which time the depositformation in grams was ascertained by determining the quantity ofdeposit on the strip, and adding thereto the amount of pentane insolublematerial in the tested oil. The rate of flow of the test oil over thesteel strip was 320 grams per hour.

The utility of the organo-boron compositions of this invention asanti-oxidants is of course not limited to hydrocarbon oils of the typerepresented in Table III. The compositions of this invention are, inlike manner, effective with synthetic oils such as polypropylene glycolcompositions of the type disclosed in United States patents: 2,425,755,2,425,845, 2,448,664, 2,457,139, 2,480,185, 2,481,278, and 2,492,955.The compositions are further useful as anti-oxidants in various othertypes of synthetic oil compositions including the polyester derivativessuch as di-2-ethylhexyl sebacate.

It is within the purview of this invention to utilize the organo-boroncompositions embraced thereby in conjunction with known additives forlubricants. These include such materials as sulfurized sperm oil, alkylthiophosphates, magnesium alkyl sulfonates, and tricresyl phosphate.Such compositions are illustrated in Table IV. It will be appreciated,particularly with respect to the alkyl thiophosphate and tricresylphosphate, that the eifect obtained may be synergistic in nature anddoes not represent the mere additive effect of the compositions blendedwith the oil.

In Table IV are recorded the results of steel strip tests of No. 1100grade aviation oil of the type previously described, blended with 15% byvolume of purified organo-boron compositions of this invention and alsoblended with the additional additives as indicated. The steel striptests and the purified organo-boron compositions utilized were the sameas those described with respect to Table III.

The lubricants containing the organo-boron compositions of thisinvention may be prepared by methods well known to the art, such as byagitation of a mixture of the lubricant and additive; heating of amixture of the lubricant and additive to effect solution; and othermethods known to the art.

The organo-boron compositions of this invention are likewise of markedutility as additives for internal combustion engine fuels such asgasoline and diesel fuels. The compositions of the invention can beemployed in such fuels in concentrations up to about 5%. Prefer- TABLEIII Wt. of Deposit Formation (e s) Quantity of Organo-Borou Compositionin Oil (Wt. Percent) 0 5 10 15 1100 Grade Aviation Oil 1.487 plus crudeorgano-boron compositions 0. 439 0. 236 0. 220

plus purified organo-boron composions 0.716 0.628 0. 435 Extracted MotorOil Stocks 2 plus puri- I lied organo-borou compositions 0. 438

Unextracted Motor Oil Stocks 3 plus purified organo-boron compo itinns0. 117

Unextracted Bright Stock plus purified organo-boron compositions 0.5150.120

94.6% Unextracted Bright Stock and 5.4% Bright Stock Extract Blend 3.598

plus purified organo-boron compositions 0. 142

% Rathnate Bright Stock 5 pluspurified organo-boron compositions--. 0.440

74% Rafiinate Bright Stool; plus purified organo-boron compositio s 1.020

1 Of the type described with reference to Figs. 1 and 2.

2 Extracted motor oil stocks were prepared by phenol extraction ofPennsylvania neutral stocks and Pennsylvania bright stock; the latterprepared by propane treatment of Pennsylvania residual stocks. Theneutral and bright stocks were characterized by the followingproperties:

Neutral Bright Raf- Stock (90% finete) Raftlnate) Vis. at; F "S. U. S173. 6 2100 Via. at 210 F- S. U. S 44.9 142 V. I 100. 2 101 CarbonResidue 0.05 0 6 3 Unextracted motor 011 stocks were composed ofPennsylvania neutra sstgcks and Pennsylvania bright stock having thefollowing characterics:

Neutral ga Vis. at 100 F 192. 0 2,444 V15. at 210 F 45.8 151 V. I 96.397.0 Carbon Re idne 0.08 1.2

4 Obtained by blending Pennsylvania bright, stock with the phone extractobtained from another sample of Pennsylvania bright stock. The brightstock utilized in both instances was the same as that; described infootnote 3. The phenol extract bright stock was characterized by thefollowing physical properties:

Bright stock extract Vis. at 100 F about 900,000 S. U. S. gisl. at 210 F981 S. S.

- about 4300 Ginfifiies'iiiii 9 10 5 Obtained by phenol extraction ofPennsylvania bright stock to a 90% galfitfiaitezyield. The bright stockwas the same as that described in Obtained by phenol extraction ofPennsylvania bright stock to a 74% raflinate yield, and having thefollowing physical properties:

1 A commercial thiophosphate anti-oxidant containing 5.8% phosphorus and9.2% sulfur.

ably the organo-boron compositions are utilized in concentrations up toabout 1.0%, based on the total weight of the fuel. A highly suitableconcentration range is from about 0.05% to about 1% based on the weightof the fuel. Specific examples of such fuels include: a conventionalstraight run gasoline derived from Pennsylvania crude oil having aboiling point range of about 100 F. to about 320 F., containing about0.5% by weight of the crude organo-boron compositions of the typeproduced by Ex-' ing, catalytic reforming from the above crude sources,or

other crude sources, combined with the above organoboron compositions;high sulfur fuel oils such as those derived from West Texas and othercrude sources; other .fuel oils derived from cycle stocks.

The fuels within the purview of this invention may be obtained byblending the organo-boron compositions of the invention with theparticular fuel in a conventional manner by methods well known to thoseskilled in the art. It' is within the purview of this invention toprepare blends embodying gasoline, diesel fuels and the like, containingfrom about 20% to about 100%, and preferably from 30% to about 90% ofthe organo-boron compositions of the invention, which concentrates maybe diluted to produce an ultimate commercial product containingorgano-boron compositions within the previously defined ranges.

It has been determined that fuels containing the organo-boroncompositions of this invention demonstrate substantially less tendencyto form deposits in internal combustion engine combustion chambers, andlikewise is attended by less pre-ignition, particularly in highcompression engines.

EXAMPLE 1 Approximately 1978.8 grams of parafiinic petroleum fraction,substantially free of aromatics and having an average molecular weightof about 235, a flash point of 275 F., a viscosity at 100 F. of 39.6 S.U. S., a viscosity at 210 F. of 31.0 S. U. S., a cloud point of 28 R, anactual pour point of 25 F., and a distillation range of from 523 F. to642 F., with an end-point of 703 F., a density at 20 C. of 0.8014, and arefractive index of 1.4456, was placed in a reaction vessel and mixedwith a synthetically compounded mixture containing about 75% by weightof boric anyhydide (B203) and about 25% by weight or ortho-boric acid(HaBOa) in an amount requisite to provide to the'ultimate reaction about2.0 equivalents of ortho-boric acid per mole of hydrocarbon startingmaterial. The mixture was heated in the reaction vessel to a temperatureof about 355 F. whereupon air was passsed through the reaction mixtureat a rate of about 2.25 cubic feet per hour per gallon of parafiinicstarting material for a period of about six hours; There was obtained acrude reaction product containing about 0.3 of chemically combinedboron.

This crude reaction product was distilled at 3 mm. pressure to a maximumtemperature of about 166 C. and there was obtained a 21.2% yield basedon the paraflinic starting material of a crude organo-boron producthaving an average molecular weight of about 587, a viscosity at 210 F.of about 74.7 S. U. S. and an acid number of about 37.0. The product soobtained was subjected to hydrolysis and sedimentation tests of the typehereinbefore described. No appreciable sedimentation was observed. About0.25 weight percent of solids resulting from hydrolysis wereprecipitated. Additives forming 12 about 0.3% by weight or less ofhydrolysis solids, under conditions of test as described above, areacceptable as lubricant additives. About 3.0% by volume is the upperlimit of sedimentation solids which may be tolerated.

The product may be converted into a purified organoboron composition byhydrolyzing with alkali and distilling the hydrolyzed productandre-esterifying the so obtained alcohols with ortho-boric acid or boricanhydride.

A blend of about 0.75% by weight of the crude prod not or the purifiedproduct of this example, with 99.25% by weight of gasoline, constitutesan excellent motor fuel which demonstrates reduced pre-ignition anddeposit forming tendencies when utilized in an automobile engine. I

EXAMPLE 2 Example 1 was repeated with the exception that there wasemployed at the initiation of the reaction a symthetically compoundedmixture containing about by weight of boric anhydride (B203) and about10% by weight of ortho-boric acid (HaBOs).

Crude organo-boron compositions obtained from the reaction mixture soproduced, were analogous to those obtained in Example 1 and demonstratedno sedimentation when blended with No. 1100 grade aviation oil.Precipitation of 0.12% by weight of solids by hydrolysis from the oilblend was observed. A blend of about 1.0% of the crude organo-boroncomposition of this example with about 99% of the diesel fuel derivedfrom Pennsylvania crude oil and having a boiling point range of about340 F. to about 625 F. is a superior product.

EXAMPLE 3 Example 1 was repeated with the exception that USP boric acidis disadvantageous as a starting material for the reason that it becomessticky under the reaction conditions.

EXAMPLE 4 Example 1 was repeated with the exception that the process wascarried out at a temperature of about 385 F. for a period of about fivehours, and boric anhydride was substituted for the boric acid-boricanhydride mixture employed in Example 1.

A product analogous to that resulting from Example 1 was obtained. Thecrude organo-boron composition was obtained by distilling the reactionmixture at about 5 mm. pressure to a maximum temperature of about C. andwas characterized by a molecular Weight of 624, a viscosity at 210 F. of96.1 S. U. S. and an acid number of 56.0. When subjected tosedimentation and hydrolysis tests in lubricating blends in the mannerhereinbeforedescribed, the product formed 1.1% by volume of the oilblend of sedimentation and 0.11% by weight of hydrolysis products.Approximately 0.5% of the crude organoboron composition of thisinventionwhen blended with about 99.5% by weight of a gasolinecontaining about 3 milliliters per gallon of tetraethyl lead, forms asuperior automobile engine fuel.

EXAMPLE 5 The process of Example 4 was repeated with the exception thatthe process was carried out at a temperature of about 305 F. for aperiod of about six and one-half product formed 1.0% by volume of solidsby sedimentation and 0.08% by weight of solids by hydrolysis.

EXAME'LE 6 The process of Example 4 was repeated with the exception thatthe process was carried out at a temperature of 325 F. for a period ofabout seven hours. The crude product obtained by distilling the reactionmixture at a pressure of 5 mm. to a maximum temperature of about 175 C.was characterized by a molecular weight of 530, a viscosity at 210 F. of89.4 S. U. S. and an acid number of 58.5. In the previously describedsedimentation and hydrolysis tests in blends with lubricating oils, theproduct of this example formed 1.5% by volume of solids bysedimentation, and 0.16% by weight of solids by hydrolysis.

EXALWIPLE 7 The process of Example 1 was repeated with the exceptionthat there was employed in the reaction mixture boric anhydride in anamount requisite to supply 1 equivalent of orthoor meta-boric acid permole of paraflinic hydrocarbon starting material, and the process wascarried out for a period of about six hours.

The crude product obtained by distilling the reaction mixture at apressure of 3 mm. to a maximum temperature of 165 C. was characterizedby a molecular weight of about 612, a viscosity at 210 F. of 90.9 S. U.S. and an acid number of 54.0. This product, when blended withlubricating oils and subjected to sedimentation tests of theaforementioned type, formed about 0.7% by Weight of solids bysedimentation.

EXAMPLE 8 The process of Example 7 was repeated with the exception thatthe process was carried out for about fifteen hours, at 355 F., thusapproaching conditions of exhaustive oxidation. The resulting productobtained by distilling the reaction mixture at a pressure of 3 mm. to amaximum temperature of 164 C. when blended with lubricants in the samemanner as the product from Example 7, formed 12.5% by volume of solidsby sedimentation, thus demonstrating the necessity to avoid exhaustiveoxidation of the reaction mixture.

EXAMPLE 9 invention.

EXAMPLE 10 The process of Example 7 was repeated with the exception thatthere was utilized ortho-boric acid in an amount requisite to provide 6equivalents thereof per mole of paraflinic hydrocarbon present in thestarting material, and the process was carried out for about two andone-half hours. The product obtained by distilling the reaction mixtureat a pressure of 5 mm. to a maximum temperature of 175 C. formed 0.65%by weight of solids by hydrolysis when blended with lubricating oils inthe manner hereinbefore described.

EXAMPLE 11 The process of Example 7 was repeated with the exception thatair was supplied to the reaction mixture at a rate of about 1.06 cubicfeet per hour per gallon of paraffinic starting material. The crudeproduct obtained by distilling the reaction mixture at a pressure of 3mm. to a maximum temperature of 166 C. was characterized by 14 amolecular weight of 453, a viscosity of 210 F. of 53.2 S. U. S. and anacid number of 27.5.

This product, when subjected to hydrolysis and sedimentation tests inlubricating oil blends of the aforementioned types, formed noappreciable sedimentation and only about 0.20% by weight of solids byhydrolysis.

EXAMPLE 12 The process of Example 7 was repeated with the exception thatin this instance there was employed the boric acid-boric anhydridemixture resulting from a previous oxidation reaction carried out inaccordance with the method of the invention. The boric acid-boricanhydride mixture employed was washed with acetone prior to utilizationin the experiment described in this example.

The product obtained by distilling the resulting reaction mixture at apressure of 2 mm. to a maximum temperature of 161 C. was characterizedby a molecular weight of 522, a viscosity at 210 F. of 66.9 S. U. S. andan acid number of 33.0.

This product, when blended with lubricating oils and tested in themanner previously described, formed no sedimentation and about 0.26% byweight of the oil blend of solids by hydrolysis.

EXAMPLE 13 The process of Example 7 was repeated with the exception thatan air rate of about 3.33 cubic feet per hour per gallon of parafiinicpetroleum fraction starting ma- EXAMPLE 14 The process of Example 7 wasrepeated with the exception that air was passed through the reactionmixture at a rate of about 4.5 cubic feet per hour per gallon ofparaffinic petroleum fraction. The crude organoboron compositionobtained from the reaction mixture by distillation to a maximumtemperature of 165 C., at 3 mm. pressure was characterized by an acidnumber of 71.7, and a viscosity at 210 F. of 166.8 S. U. S.

This crude product formed 10.5% by volume of solids by sedimentation and0.35% by weight of solids by hydrolysis, when subjected to thepreviously described tests in oil blends. This example demonstrates theinoperability of air rates substantially exceeding the upper limithereinbefore described for the process of this invention.

EXAMPLE 15 42 gallons of a paraflinic petroleum fraction, having anapproximate molecular weight of 175, a flash point of 180 F., aviscosity at F. of 31.5 S. U. S., a viscosity at 210 F. of 28.5 S. U.8., showing a kattwinkle loss of 0.0%, was mixed with 5,170 grams ofboric anhydride and grams of manganese naphthenate, containing about 6%by weight of manganese. Air was passed through this reaction mixture ata rate of about 3.0 cubic feet per hour per gallon of petroleumfraction, for a period of about four hours. The purified organoboroncomposition obtained therefrom was useful as an oil additive.

EXAMPLE 16 42 gallons of a petroleum fraction having an averagemolecular Weight of 150, a viscosity at 100 F. of 1.169 centistokes, aboiling range of 367 F. to 439 F., and showing a kattwinkle loss ofzero, were blended with about 30 pounds of boric anhydride and 0.25pound of manganese naphthenate of the type described in Example 15 15.Air was passed through this mixture at a rate of about 3.0 standardcubic feet per hour per gallon of hydrocarbon, for a period of aboutseven hours. The

reaction temperature was maintained at 310 F. and the pressure in thereaction vessel at 25 pounds per square inch guage. The reaction mixturewas distilled'to remove the lighter fractions and the residue therebyobtained was recovered as the product. This product was hydrolyzed withboiling water. The alcohols released by hydrolysis were removed bydistillation. A yield of 12 weight percent of the charge'was obtained inthe form of alcohols having to 11 carbon atoms per molecule. Theunreacted hydrocarbon recovered from the first distillation step may beagain utilized in the production of organo-boron compositions.

Alcohols may be obtained from any of the reaction products described inthe examples of this application in like manner. Aqueous caustic,particularly aqueous sodium hydroxide, may be availed of in lieu ofboiling Water to effect hydrolysis of the resulting products.

EXAMPLE 17 2113.2 grams of a petroleum fraction having an averagemolecular Weight of 352, a flash point of 400 F., a viscosity at 100 F.of 103.2 S. U. S., a viscosity at 210 F. of 39.6 S. U. S., a cloud pointof +4 F., showing a kattwinkle loss of 5.5%, were admixed with 69.7grams of boric anhydride and 2.1 grams of manganese naphthenate of thetype described in Example 15. Air

was passed through this mixture at a rate of about 2.25 cubic feet perhour per gallon of petroleum fraction, for a period of about seven andone-half hours. By distillation, there may be obtained from the reactionmixture so produced, a crude organo-boron composition useful as alubricant or fuel additive.

We claim:

1. A process'for preparing organo-boron compositions which consistsessentially of passing a free-oxygen containing gas through a normallyliquid parafiinic petroleum fraction having a boiling point in the rangeof about 350 F. to about 800 F., maintained at a temperature within therange of about 305 F. to about 385 F.; there being available forreaction in said fraction from about 1 to about 3 chemical equivalentsof an acid, selected from the group consisting of ortho-boric acid andmeta- .boric acid, per mole of paraflinic hydrocarbon; said gas beingpassed through said fraction at a rate requisite to provide not morethan about 0.6 cubic feet of oxygen per hour per gallon of saidfraction; to produce a crude reaction product containing at least about0.2% by weight of chemically combined boron.

2. The process of claim 1, wherein the free-oxygen containing gas ispassed through the normally liquid paraffinic petroleum fraction at arate requisite to pro-v ortho-boric acid and meta-boric acid, a mixturecontaining from about 50% to about 90% by weight of boric anhydride, andfrom about 50% to about 10% by weight of an acid selected from the groupconsisting of orthoboric acid and meta-boric acid.

6. The process of claim 5, wherein the mixture of boric anhydride and anacid selected from the group consisting of ortho-boric acid andmeta-boric acid, consists essentially of the boric acid and residueobtained from a previous oxidation reaction carried out in accordancewith the method of claim 1.

7. The process of claim 1 carried out at a temperature of from about 340F. to about 365 F.

8. The process of claim 1 in which the free-oxygen containing gas ispreheated to a temperature of from about 160 F. to about 210 F. prior toutilization in the process of the invention.

9. The process of claim 1 carried out in a cylindrical vessel in whichthe ratio of the depth of the liquid reaction mixture to the area of thecross-section of the cylinder is at least about 2.

10. The process of claim 1 carried out in the presence of an oxidationcatalyst.

11. The process of claim 10, wherein the oxidation catalyst is selectedfrom the group consisting of manganese naphthenate, manganese stearate,copper naphthem ate, cobalt napthenate, and nickel napthenate.

12. The process of claim 1, wherein the starting material is a normallyliquid, mineral-oil soluble, paraflin having a boiling point within therange of from about 500 F. to about 600 F.

13. The process of claim 1, wherein the normally liquid paraffinicpetroleum fraction utilized has an overall boiling point range not morethan about 100 F.

14. The process of claim 1, in which a basic inorganic material, asaturated solution of which at about F., is characterized by a pH ofbetween about 7.0 and about 10.0, is included in the reaction mixture ina quantity of from about 0.5% to about 5.0% by weight, based on thequantity of parafiinic petroleum fraction utilized.

15. The process of claim 14, wherein the inorganic basic material isselected from the group consisting of the alkaline metal borates, the,alkaline earth metal borates. and aluminum hydroxide.

16. The boric acid ester containing compositions produced according tothe process of claim 1.

17. The boric acid ester containing compositions produced according tothe method of claim 15.

18. Boric acid ester containing compositions obtained by distilling thecrude reaction mixture produced by the method of claim 1. s

19. The boric acid ester containing compositions produced according tothe method of claim v1, having incorporated therein organic carbinolcompounds in an amount sufficient to impart hydrolytic stabilitythereto.

20. The boric acid ester containing compositions of claim 19, in whichthe organic carbinol compound is selected from the group consisting ofthe polyethylene glycols, the polypropylene glycols, glycerin,pentaerythritol, mannitol, sorbitol, and the monohydric paraffinalcohols, having from 5 to 20 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES J.'A. C. 8., vol. 67, December 1945, pages 2150-52. (Copy in260-462.) V

1. A PROCESS FOR PREPARING ORGANO-BORON COMPOSITIONS WHICH CONSISTSESSENTIALLY OF PASSING A FREE-OXYGEN CONTAINING GAS THROUGH A NORMALLYLIQUID PARAFFINIC PETROLEUM FRACTION HAVING A BOILING POINT IN THE RANGEOF ABOUT 350* F. TO ABOUT 800* F., MAINTAINED AT A TEMPERATURE WITHINTHE RANGE OF ABOUT 305* F. TO ABOUT 385* F.; THERE BEING AVAILABLE FORREACTION IN SAID FRACTION FROM ABOUT 1 TO ABOUT 3 CHEMICAL EQUIVALENTSOF AN ACID, SELECTED FROM THE GROUP CONSISTING OF ORTHO-BORIC ACID ANDMETABORIC ACID, PER MOLE OF PARAFFINIC HYDROCARBON; SAID GAS BEINGPASSED THROUGH SAID FRACTION AT A RATE REQUISITE TO PROVIDE NOT MORETHAN ABOUT 0.6 CUBIC FEET OF OXYGEN PER HOUR PER GALLON OF SAIDFRACTION; TO PRODUCE A CRUDE REACTION PRODUCT CONTAINING AT LEAST ABOUT0.2% BY WEIGHT OF CHEMICALLY COMBINED BORON.